<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script type="text/javascript">
			function add() {
				var input1 = document.getElementById("num1");
				var input2 = document.getElementById("num2");
				var num1 = input1.value;
				var num2 = input2.value;
				var result = parseInt(num1) + parseInt(num2);
				var resultInput = document.getElementById("result");
				resultInput.value = result;
			}
			
			function sub() {
				var input1 = document.getElementById("num1");
				var input2 = document.getElementById("num2");
				var num1 = input1.value;
				var num2 = input2.value;
				var result = parseInt(num1) - parseInt(num2);
				var resultInput = document.getElementById("result");
				resultInput.value = result;
			}
			
			function cal(type) { // + - * /
				var input1 = document.getElementById("num1");
				var input2 = document.getElementById("num2");
				var num1 = input1.value;
				var num2 = input2.value;
				var result;
				switch (type){
					case "+":
					result = parseInt(num1) + parseInt(num2);
						break;
					case "-":
					result = parseInt(num1) - parseInt(num2);
						break;
					case "*":
					result = parseInt(num1) * parseInt(num2);
						break;
					case "/":
					result = parseInt(num1) / parseInt(num2);
						break;
					default:
						break;
				}
				
				var resultInput = document.getElementById("result");
				resultInput.value = result;
			}
		</script>
	</head>
	<body>
		<table>
          <tr>
             <td><img width="50px" height="50px" src="../img/shop.png" /></td>
             <td colSpan="3">购物简易计算器</td>
          </tr>
          <tr>
             <td>第一个数</td>
             <td colSpan="3">
                 <input type="text" id="num1" />
             </td>
          </tr>
          <tr>
             <td>第二个数</td>
             <td colSpan="3">
                 <input type="text" id="num2" />
             </td>
          </tr>
          <tr>
             <td>
                 <input type="button" value="+" onclick="cal('+')"/>
             </td>
             <td>
                 <input type="button" value="-" onclick="cal('-')"/>
             </td>
             <td>
                 <input type="button" value="*" onclick="cal('*')"/>
             </td>
             <td>
                 <input type="button" value="/" onclick="cal('/')"/>
             </td>
          </tr>
          <tr>
             <td>计算结果</td>
             <td colSpan="3">
                 <input type="text" id="result" />
             </td>
          </tr>
       </table>
	</body>
</html>
